Logitech Z-5500 cable issue

Hi there guys. Am fairly new to the forum and after a bit of research here and with my trusty friend mr google I have come up a bit empty handed.

Basically I have the fantastic logitech Z-5500 speaker system which I pair with my equally fantastic MacBook Pro. A damn nice couple I must say To avoid wires I purchased the Zoom iHiFi which allows me to send the sound signals from my macbook to my logitech speakers via bluetooth.

Again a lovely idea but when I pause the music on the laptop there is a lot of background noise and hissing. Not enough to completely piss me off but its there. The iHifi plugs into the speakers via a 3.5mm Stereo Mini Jack to Stereo RCA cable and unfortunately there is no digital input or coaxial input on the iHifi receiver.

Basically I am wondering what is the best way to reduce this background noise and get my system nicly balanced?